Unpiggable Pipeline Solutions

Conference Program Abstracts

DAY 1

INNOVATIONS IN UTILITY PIGGING

Small-diameter cleaning pigs

Doug Batzel, Batzel Engineering, Moosic, PA, USA

The paper reports on the solution to a problem cleaning small diameter pipes, 1” through 4”. There was a need to clean coil tubing after it was used in a well bore where the product pumped through tubing stuck to the walls. Flushing was not sufficient to dislodge the debris. Premature failure of the tubing due to corrosion was a major problem.

In the coil tubing business, the only solution was to use a piece of high density foam and flush it through the tubing. Flushing was ineffective. Adding to the problem is the constantly changing curvature. Another problem was that effective miniature brushes were nonexistent.

Once a pigging solution was engineered, the next problem was that, since the coil tubing was mounted, the pig needed to turn a 90-degree bend without getting stuck, harming the pig, thereby reducing the ability to conform to the constant radius change, damaging the bristles thereby limiting the cleaning effectiveness and the pig could not damage the inner surface of the coil tubing which would allow corrosion the get a foothold. And the pig should be reusable.

This paper will discuss all of the steps taken to design and build a successful pig.  

Wax removal from large-diameter pipes using ice slurries

Steve Wheeler, iNPIPE Products, Brompton on Swale, UK
Dr. D. Rhys, Suez Advanced Solutions Limited, Bristol, UK

Ice Pigging is a cleaning technique, mature in the water / wastewater industries, which is being developed for the Oil and Gas industry.

A high-solids ice slurry is pumped under pressure to deliver a wall shear stress on the pipe, cleaning it through physical abrasion. Made of just water and salt, ice pigs do their cleaning, unblocking, debris entraining and transport before melting back into their original components (commonly salt and water); offering a physical clean thousands of times more effective than flushing, without chemicals or risk of getting stuck.

The trails, which are the subject of this paper were commissioned by Royal Dutch Shell plc, using funding from their Gamechanger innovation program.

Development of smart pig technology for launching and receiving through pigging valves

Steve Banks, i2i Pipelines, Manchester, UK

Pigging valves are a common and valuable addition to pipeline systems around the world and are a well proven and cost effective way to make a pipeline system piggable. They are easy to operate, take up little space, and are a cost-effective way to introduce and recover pigs from a pipeline.

Pigging valves are deployed extensively on small bore gathering lines of the shale assets in Western Canada and the US, where frequent cleaning is required and the ease of operation of pigging valves makes them a popular choice amongst operators. Pigging valves can also be extremely valuable in tight spaces offshore, like in the turret of an FPSO, where there is little or no room for conventional launchers /receivers.

Up to now pipeline operators could only deploy standard PU type cleaning pigs through pigging valves, this has led to limitations in gathering inspection data which affects the overall integrity management of the gathering lines. Given the changing government regulations on the inspection of gathering lines in the US and the number of pipelines that have pigging valves in place, there is a real demand within industry to develop inspection tools that can be deployed from the valves.

i2i, with help from a pig valve manufacturer, have been working to develop a new generation of single module smart pig that will allow pipeline operators to deploy inspection pigs through their existing pigging valves. Pipeline operators may see significant benefits in efficiency, cost savings and the ability to collect inspection data more frequently. All this with little disruption to operations and an improvement in integrity management.

This paper will look at the challenges of developing inspection tools that can be launched through pigging valves and some of the operational challenges that need to be considered. Particular challenges are the size of the smart pigs needed, ranging from 2” to 10”, the ability to handle high pressure, the ability to inspect through internal liners and the ability to operate in gas as well as other mediums.

The paper will cover a real world deployment to illustrate the benefits and challenges of developing new smart pigs for this application.

CROSS-OVER TECHNOLOGIES

Nondestructive evaluation of heat exchanger tubes and pipelines using electromagnetic waves

Dr. Ronald Focia, Pulsed Power Laboratories, Edgewood, NM, USA
John DeWees, WaveTrue, New York, NY, USA

This paper describes WaveTrue Science + Technologies EMW-I™ technology and the use of it to develop minimum detectability thresholds, range and resolution estimates for anomalies of various compositions. First, the details of the method and its implementation are discussed.  Although the EMW-I™ technology can be applied to tubes and pipes of any diameter, this paper focuses primarily on its application to larger diameter pipes.  Data was collected on an 8.625 inch by 0.322 inch wall thickness carbon steel test loop for various volumes of anomalies consisting of metallic gain and loss, paraffin, water and hydrocarbon (oil). From these data, the instrument response vs anomaly volume at various distances from the probing location were used to determine attenuation and minimum detectability thresholds versus distance. Theoretical relations for how attenuation varies with pipeline inner diameter can then be used to scale these numbers to other pipe diameters.

Comparison and overlaps of tools for internal inspection of pipelines and in human blood vessels

Dr. Stephen Igo, DeBakey Heart & Vascular Center, Houston Methodist Hospital, Houston, TX, USA

DEVELOPMENTS AND EXPERIENCE WITH ROBOTIC INSPECTION TECHNOLOGY

Data quality of robotic pipeline inspection methods in addressing pipeline threats

Rod Lee and Francis Gracias, Pipetel Technologies , Toronto, ON, Canada
Paul Monsour, Southern California Gas Co., Los Angeles, CA, USA

Robotic pipeline inspection method has been more widely used for integrity assessment of natural gas and liquid product pipelines over the past 5 years.  While the operational advantages offered by this method may be more well-known and documented, there is relatively little literature on the quality of data and results acquired by a pipeline inspection robot and the specific threats that can be found.

The purpose of this paper is to examine the suitability of robotic pipeline inspection methods in addressing specific pipeline threats, including surface corrosion, internal and material anomalies, deformations, construction features, cracks and crack-like-features, and other useful pipeline features and characteristics including material verification.  The authors will provide results and specific examples with evidence of various pipeline threats and features, found by robotic pipeline inspection, that were subsequently excavated and validated.

This paper will also compare the quality of data acquired by conventional free-swimming inline inspection tools and robotic inline inspection tools.   We will also examine the limitations of robotic inline inspection method in addressing specific pipeline threats and the opportunities that exist in addressing them.

Robotic crawler ILI of an unpiggable 10” natural gas pipeline

Steven Trevino, Diakont, Houston, TX, USA

Diakont Advanced Technologies was commissioned to assess the integrity of a natural gas pipeline that was partially buried under an urban area on a major North American pipeline. The company used a reduced size robotic crawler to successfully navigate a 10 in. pipe. The size of this pipe has previously been a limitation, making it ‘unpiggable’ using other ILI methods.

Designated as a high consequence area (HCA) due to being located in a densely populated area, this section of pipeline had never been inspected. Low flow, its narrow 10 in. internal diameter (ID), and its characteristics (tight bends, plug valves, etc.) made the pipe unsuitable for traditional smart pigging. However, the United States’ federal Pipeline and Hazardous Materials Safety Administration (PHMSA) regulations require specific integrity management programs in HCAs.

The pipeline’s inspection challenges could have forced its operator to replace an entire quarter of a mile length of pipe if they could not inspect the line effectively and on schedule. The technology gap between the inspection requirements and the available tooling forced the industry work with pipeline service vendors to develop a suitable solution.

New technology: reduced size and self-propelled
The new robotic crawler tooling traverses challenging pipeline geometries using a ruggedized multiple track system, which allows for navigation across horizontal surfaces. Moreover, the tool can extend the tracks to the pipe wall for stabilization. This arrangement provides the traction that is necessary to hold the tool rigidly in place while inspecting difficult-to access pipeline applications (such as inclines and vertical sections), where conventional ILI tools may not be feasible. This Sprinter system moves at a deliberate pace to provide accurate mapping of anomaly locations within the pipeline. Being self-propelled and bidirectional, the Sprinter can also be deployed and retrieved from a single access point, which was another key feature in its selection for this inspection program.

This presentation will provide details on the NDT tooling along with a case study for inspecting the unpiggable natural gas pipeline.

In-line MFL inspection of a subsea vent line with a self-propelled robotic unit

Corey Richards, ROSEN Group, Lingen, Germany
Frank Mueller, ROSEN Group, Dubai
Benny Hendra Syamsuddin, ROSEN Group, Kuala Lumpur, Malaysia
Daniel Schaller, ROSEN Group, Stans, Switzerland

Offshore subsea vent lines were never designed to be internally inspected. They are therefore categorized as unpiggable pipelines. Operators, however, consider these subsea vent lines a critically important element of their entire system, and are keen to gain a clear picture of the integrity of their vent lines. Suitable inline inspection solutions are therefore in demand.

Vent lines are indeed a crucial part of processing systems, and are utilized to ensure safe disposal of the excessive hydrocarbon gas inventory in the installation during operation, emergency, or shut down situations. Since the gas cannot be stored or commercially utilized and must therefore be released, it is essential that the risk of fire and explosion be reduced by venting the excessive gas at a safe distance from a platform.

Challenges to performing inline inspection for subsea vent lines include:

  • No conventional access for ILI tools available
  • Pipeline can only be accessed from the main platform
  • No or very low flow and pressure
  • No previous inspection knowledge
  • Cleanliness is unknown

To meet these challenges, a sophisticated 10” & 12” crawler unit was developed that was capable of safely traversing non-operational vent lines, including the riser, up to a distance of 2 km. The self-propelled robotic propulsion unit utilized for the inspection combines various elements, including high-resolution bidirectional MFL technology. The specialized cam design driving components provide an increase in pull force capabilities, allowing the utilization of extensively tested high-resolution MFL technologies. Furthermore, this design allows for both vertical and horizontal bidirectional movement capabilities, which were critical for this application. This provides the operator with a full integrity assessment for the asset without reduction in data quality or the need to validate new measurement technologies.

This paper outlines the various safety mechanisms that are often overlooked when utilizing self-propelled inspection technologies. These mechanisms, both procedural and mechanical, allow for the inspection tool to traverse various obstacles, such as small deformations and debris, while also offering various failsafe options for tool retrieval in the event of a malfunction or when encountering an unpassable obstacle.

Recently, this system successfully completed multiple subsea vent line inspections in Sarawak Basin, East Malaysia. The tailored solution was selected because of the capabilities to provide high pull force, cope with the uncertain conditions of such vent lines, and produce high-resolution results. This paper discusses in detail the tool design, performance specification, and extensive tests performed at ROSEN Technology and Research Center facilities, as well as the specific project aspects of the subsea vent line inspections. The solutions outlined in the paper will not only highlight the capabilities to inspect complicated offshore assets, but will further discuss how these solutions can be applied to other complex assets in need of inspection solutions.

TOOL SELECTION, CHALLENGING PROJECTS

Not all pipelines are constructed equal – how to determine the right inspection technology based on expected damage mechanisms

Dan Revelle and Ron Maurier, Quest Integrity, Houston, TX, USA

Determining an appropriate inspection technology is the critical first step in performing a successful pipeline inspection. A number of significant and potentially prohibitive factors must be considered to determine an inspection method that accurately detects damage mechanisms likely present within a pipeline. Theoretically, typical damage methods including corrosion, erosion, pitting, third-party damage and deformation are reliably detectable by all pipeline inspection methodologies. However, circumstantial difficulties during pipeline inspections, including atypical environments, construction-related damage, and unusually hard-to-find defects require specialized detection. Having an understanding of what damage mechanisms are expected within any given pipeline largely affects the type of tool technology utilized during an inspection.

Damage mechanisms are not, however, the sole determining factor when choosing an appropriate inspection methodology. The operator must also take into consideration the pipeline’s accessibility, configuration, environmental constraints, product throughput and associated cost, as these factors can significantly limit a tool’s detection capability.

This paper will discuss the spectrum of damage mechanisms that cause integrity concerns for unpiggable pipelines, as well as the other critical factors that complicate the tool selection process. A specific focus will be on addressing each inspection methodology’s ability to successfully detect types of expected pipeline damage at specific pipeline locations. Although there are benefits in using various types of technologies to validate integrity (MFL, hydrostatic testing, ultrasonics, spot UT, etc.), there are a number of limiting factors to consider for each methodology, such as data coverage at bends, pipeline supports, pipe tees, operational constraints, and the full cost of each procedure as part of an integrity program. Real-world case study examples will be used to illustrate.

Facility integrity - underground and underutilized piping inspection

Kevin Ostergren, Phillips 66, Houston, TX, USA

This presentation will cover managing underground and underutilized piping segments using a Facility Integrity Risk Assessment program (FIRA). Some of the factors involve include:

•     Determining appropriate inspection techniques based on risk, product, accessibility and age of equipment
•     Evaluate contracted inspection personnel
•     Conducting review of inspection results for accuracy and code compliance
•     Understanding current integrity status of equipment acquired through acquisition

 

DAY 2

CHALLENGING INSPECTION PROJECTS (cont’d)

Pigging four-phase crude pipelines for flow assurance, corrosion control, and inspection: challenges and solutions

Everett F. Johnson, Sr. and Randy Heath, Marathon Oil Eagle Ford Asset Team, Kennedy, TX, USA

Pipeline systems and production piping in unconventional oil & gas fields are extremely difficult to pig due to configuration, flows, and process conditions. Nevertheless, these pipelines require routine pigging for flow assurance, corrosion control, and inspection. Multi-phase flows in oil & gas pipelines include gas, oil, water, and paraffin/solids. This paper will discuss the challenges to pigging unconventional oil & gas pipelines presented by multiple connections and piping configurations, unknown configurations, and process conditions such as multi-phase flows, variable flows, and liquid slugging. One operator’s unique solutions and project experiences will be shared, for both maintenance pigging and smart pig inspections.

Inspection of unpiggable large-diameter pipelines utilizing tri-axial MFL sensor technology

Paris Brad, Troy Hempel and Dale Simpson, Baker Hughes, Calgary, AB, Canada
Aaron Schartner and John Tang, TransCanada Pipelines, Calgary, AB, Canada

Inline inspection tools are one of the primary methods for inspecting and monitoring the condition of pipelines against integrity threats by pipeline operators for over 40 years. Technology has been in place to allow smaller diameter pipelines to have Inline Inspections completed without the use of permanent launcher or receiver facilities through the use of tethered (wireline) Inline Inspection tools. For some pipeline segments with diameters greater than 30 inches in size, technical and economic conditions exist that do not make the installation of permanent launch or receive facilities feasible. In addition, service companies have limited their offerings to smaller diameter tethered inspections with the majority having been performed between 2 and 20 inches in diameter, where the pipeline outage requirements, tool pulling limitations, costs, and other technical constraints have restricted the development of the tethered inspection service in larger diameter pipelines.

Traditionally, the larger diameter pipeline segments without launcher or receiver facilities could not be assessed by Inline Inspection and would be assessed by hydrostatic testing and direct assessments. Inline Inspection for many pipelines is the preferred method of assessment as it enables condition monitoring of pipeline segments. The feature-specific information allows operators to accurately manage the potential threats on the inspected pipeline segment. TransCanada approached Baker Hughes for a solution to inspect large inch pipelines (>30”) utilizing their Tri-Axial Magnetic Flux Leakage (MFL) technology on sections that do not have launcher or receiver facilities.

This paper describes the engineered, integrated service approach that resulted in the successful tethered inspection of several pipelines up to 48 inches in diameter with high resolution MFL inspection technology. Furthermore, the technical, logistical and project management challenges inherent in the project from both the operator and service company perspectives are discussed, including the mitigation of HSE risks and the engineering control measures implemented.

Inline inspection of multi-diameter gas pipelines at low pressure

Stefan Krieger and Michael Pieske, ROSEN Group, Lingen, Germany
Stefan Vages, ROSEN Group, Calgary, Canada

Most of today’s gas transmission and distribution systems can be inspected using available inline inspection technology. While this is applicable to the majority of pipeline systems, a certain portion of pipeline segments remains unpiggable or difficult to inspect. When looking to properly assess the integrity of these assets, different options for data gathering are usually evaluated, e.g. hydro-testing, ECDA, and inline inspection. Since inline inspection is the preferred assessment method and often also the most cost effective, new solutions for these more complex pipeline segments are required.

Pipeline segments that cannot be inspected with available technology typically consist of multiple challenges at once. While each of these challenges individually has already been overcome — e.g. the passage of 1.5D 90° back-to-back bends, successful completion of surveys in a low-pressure environment, or the application of inline inspection in multi-diameter pipeline systems — the combination of several of them requires new systems to adequately address the corresponding problems.

The challenges related to successfully completing inline inspections of multi-diameter gas pipelines at lower pressure levels include:

  • Proper preparation of the pipeline for ILI — special multi-diameter cleaning solutions
  • Achieving the desired data quality
  • Reaching a balance between sufficient seal and reduced friction
  • Passage of complex pipeline features – e.g. back-to-back 1.5D 90° bends

The ROSEN Group is currently developing a suite of multi-diameter ILI tools — in particular 10/12″, 12/16″ and 24/30″ tools among other sizes — that are specifically designed to accommodate the challenges of low operating pressures and complex pipeline geometries. The development program also encompasses the creation of cleaning solutions that effectively address the challenges posed by multi-diameter pipelines. These new inspection solutions provide pipeline operators with more options for gathering the same quality information on their challenging pipeline segments as on their already inspected segments.

This paper discusses the considerations going into the project, design requirements, testing programs, and relevant field experience. Additionally, the limitations of the technology in the corresponding environment will be discussed.

NEW INSPECTION TOOLS, TECHNOLOGIES AND APPLICATIONS

INCOTEST tool for ROV deepwater inspection of unpiggable pipelines

Roger Warnock and Robin Bennett, Delta Subsea, Houston, TX, USA

The INCOTEST (INsulatedCOmponentTESTing) Tool is based on the pulsed eddy current principle and is a reliable way to survey ferrous pipes and vessels through their thermal insulation and protective coatings.

The first prototype system to take the INCOTEST tool subsea can be remotely operated by ROV and maneuvered by the ROV manipulator. The system consists of 12 INCOTEST probes mounted on a frame with flaps hydraulically operated.

The benefits of Pulsed Eddy Current Testing and INCOTEST are:

  • Detection of surface and subsurface corrosion
  • Measurements of average remaining wall thickness within the interrogated area (footprint)
  • No contact needed for the measurement
  • No special surface preparation needed
  • Measurement through marine growth, fouling and concrete
  • Measurements performed in-line and done in depths down to 3000 meters (9842 feet)
  • Component evaluation at variable depths achievable through measurement at a range of frequencies or through different coil sizing
  • No consumable chemicals required
  • Fast: up to 1,000 measurements a day
  • Operates on batteries or mains ROV power

The more traditional inspection techniques are visual inspection and ultrasonic testing. The presentation will discuss several advantages of INCOTEST over ultrasonic testing in these conditions.

ILI in a 2-inch pipeline – miniaturized tool development for arctic environments

Basil Hostage and Dr Daniel Schaper, 3P Services, Lingen, Germany
Rodney Evans, Coffman Engineers, Anchorage, AK, USA

This paper describes the ambitious project to develop a fleet of tools (profile, geometry tool, MFL) to inspect a 2“ pipeline located on the North Slope of Alaska. The 34.6 mile long line transports arctic heating fuel from a Central Processing Facility to a western satellite camp facility, and has never been inspected. To prevent damage to the fragile arctic tundra, year-round access is available only by helicopter. Winter access is available by snowmobile or Sno-Cat when snow cover is deemed adequate. There were two defining challenges for the project. The first was to create an MFL module that could fit inside the restricted volume and still be capable of magnetically saturating the pipe wall. The other challenge was to develop a complete working system capable of functioning in a temperature environment of -20°F, or less. The tools were developed and successfully verified in a test loop in Germany. All tool components like cups, electronics or sensors were specially checked to meet the temperature requirements.

The development is strictly project related. All equipment is tailored specifically to this pipeline. The authors consider this a stand-alone project. There is no expectation that a general inspection market exists for ILI of 2” pipelines. If there should be opportunities in this dimension, then the tool design needs to be re-considered for the specific case.
This paper describes what an ILI vendor can achieve who has wide specific tool development know-how and flexible engineering facilities.

Developments in remote magnetic monitoring of carbon steel pipelines to locate and measure abnormal stress

Hamed Habibi, Paul Jarram and Chau Vo, Speir Hunter Ltd, Newark, UK
Presented by Michael Staite, Speir Hunter North America, Nisku, AB, Canada

This paper outlines characteristics and field verification of a novel remote sensing technique developed to detect localized abnormal pipe wall stress by mapping variations in the magnetic field around pipelines. Corrosion, cracks, metallurgical defects and external forces on a pipe resulting from influences such as ground movement lead to areas of increased localized stress in pipelines that are under pressure. A direct relationship has been mathematically developed for relating magnetic field characteristics to the magnitude of this stress. The method is non-invasive and reports the geometric center of areas of localized stress in megapascals, accurate positioning of girth welds and three-dimensional mapping of the pipeline route including depth of cover, all to centimeter accuracy.

This game-changing inspection method has a totally revolutionary approach to integrity management by monitoring stress without measuring the changes in mass of metal or the geometry of a pipe wall. Categorizing the type of defect, finding defect clock position or precise measurement of defect geometry is no longer needed for making maintenance decisions. Having a combination of defects such as cracks and dents at the same time can be monitored effectively and repair schedules prioritized by using this technology in conjunction with others, for example coating inspections to monitor the condition of the pipe wall under coating damage.

Comprehensive field verifications of this inspection method have been conducted in recent years, including the excavation of four indications identified by this method, following a survey in Europe. Observations following these four excavations are detailed in this paper to demonstrate the effectiveness of this technique, notably the detection of localized stress in a pipe wall. The benefits of using this method on both unpiggable and piggable pipelines are also described, in addition to its potential application for inspection of challenging lines.

PRCI research update

Hans Deeb, PRCI, Houston, TX, USA

PRCI will provide an update on current research into solutions for unpiggable pipeline assessments as well as related technology research.  Recent Final Reports on hydrostatic testing guidelines and qualification and testing of ILI vendor specifications in blind tests against real and manufactured defects will be discussed, as well as ongoing work specifically in the area of difficult-to-inspect pipelines at the PRCI Technology Development Center (TDC) in Houston.

Magnetic Tomography Method (MTM) as a new approach for pipeline integrity and health assessment

Igor Kolesnikov, TRANSKOR Group, Inc., Houston, TX, USA

The presentation describes a new approach in pipeline integrity based on the evaluation of actual mechanical stresses by 3D-space measurements of a constant magnetic field distributed along the pipeline axis. Using magnetic tomography (MTM), the technology has been deployed effectively as a risk-based inspection tool for underwater pipelines under the trade name Aqua MTM.

Inspection results are obtained by determining the relationship of parameters between magnetic and mechanical fields of the pipeline. As a result, MTM identifies the exact location of areas with increased concentration of mechanical stresses (VAT anomalies) and interprets the threat level based on the values of maximum local stress.

Common pipeline safety procedures determine the values ​​of mechanical stresses obtained by calculations (FEM, Rstreng, etc.) based on the distribution of defects, their size and location as reported by standard ILI and NDE surveys or ECDA/ICDA practices. It should be noted that selection of dig areas for testing is based on subjective expert assessments and experience. The safety of the entire pipeline is based on extrapolation of these results to the entire length. Therefore, the risk of missing a serious defect remains high, since less than 2% of the length of pipeline is monitored.

MTM was developed in 2001 to monitor pipelines which could not be inspected with ILI tools. Using the technology to perform continuous magnetic field scanning of the entire length of a pipeline, dependent relationships between the magnetic and mechanical properties of pipe steel were found. Between 2002 and 2010 many tests were carried out, including search and evaluation of: defects and clusters of different types of defects; stress concentration zones in conditions of rough terrain, both under internal pressure and absence of pressure; and the weakest section on a pipeline of limited length.

In 2011 MTM was adapted to evaluate the state of underwater pipelines (Aqua MTM™). Essentially, the technique involves continuous scanning of the 3D magnetic field along the pipeline axis, construction of a stress distribution map, selection of limit criteria for specific pipeline operating conditions, and determining of VAT anomalies associated with changes of mechanical stresses. The tools have been deployed using ROVs, AUVs and divers.

The paper will be briefly present a number of examples of the application of MTM/Aqua MTM to assess various types of stresses, such as:

  • Hoop stress resulting from internal corrosion growth. Rill (brook)/pitting corrosion. Features of the application of Aqua MTM, conditions of use.
  • Axial stress. Examples of using MTM in conditions of unstable soil, ground disturbance and motions due to increased seismic activity, hilly and swampy areas. The experience of using Aqua MTM for free-span evaluation.
  • Experience using MTM in difficult, inaccessible or impossible NDE areas, and assessment of pipeline condition using monitoring studies.

The tool and technology were developed with the support of PETRONAS and have been in field use since 2012.


 Organized by:

Clarion Technical Conferences     Tiratsoo Technical

 Platinum Sponsor

A. Hak   

 Gold Sponsors

A. Hak    Rosen

 Silver Sponsor

Pipetel Technologies   

 Supported by:

Pipelines International     PIPE     Journal of Pipeline Engineering              PRCI     PPSA     PGJ     Oil and Gas Journal     Inspectioneering